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/*! \file
    \brief
*/

#pragma once

#include "cutlass/cutlass.h"
#include "cutlass/numeric_types.h"
#include "cutlass/arch/arch.h"
#include "cutlass/device_kernel.h"

#include "cutlass/gemm/gemm.h"
#include "cutlass/gemm/threadblock/threadblock_swizzle.h"
#include "cutlass/gemm/kernel/gemm_universal.h"

#include "cutlass/gemm/kernel/default_gemm_universal.h"
#include "cutlass/gemm/device/default_gemm_configuration.h"
#include "cutlass/gemm/device/gemm_universal_base.h"

#include "cutlass/layout/permute.h"

////////////////////////////////////////////////////////////////////////////////

namespace cutlass {
namespace gemm {
namespace device {

/////////////////////////////////////////////////////////////////////////////////////////////////

/*! 
  GemmUniversal is a stateful, reusable GEMM handle.  Once initialized for a given GEMM computation
  (problem geometry and data references), it can be reused across different GEMM problems having the
  geometry.  (Once initialized, details regarding problem geometry and references to workspace memory
  cannot be updated.)

  The universal GEMM accommodates serial reductions, parallel reductions, batched strided, and 
  batched array variants.
*/
template <
    /// Element type for A matrix operand
    typename ElementA_,
    /// Layout type for A matrix operand
    typename LayoutA_,
    /// Element type for B matrix operand
    typename ElementB_,
    /// Layout type for B matrix operand
    typename LayoutB_,
    /// Element type for C and D matrix operands
    typename ElementC_,
    /// Layout type for C and D matrix operands
    typename LayoutC_,
    /// Element type for internal accumulation
    typename ElementAccumulator_ = ElementC_,
    /// Operator class tag
    typename OperatorClass_ = arch::OpClassSimt,
    /// Tag indicating architecture to tune for.  This is the minimum SM that
    /// supports the intended feature. The device kernel can be built
    /// targeting any SM larger than this number.
    typename ArchTag_ = arch::Sm70,
    /// Threadblock-level tile size (concept: GemmShape)
    typename ThreadblockShape_ = typename DefaultGemmConfiguration<
        OperatorClass_, ArchTag_, ElementA_, ElementB_, ElementC_,
        ElementAccumulator_>::ThreadblockShape,
    /// Warp-level tile size (concept: GemmShape)
    typename WarpShape_ = typename DefaultGemmConfiguration<
        OperatorClass_, ArchTag_, ElementA_, ElementB_, ElementC_,
        ElementAccumulator_>::WarpShape,
    /// Instruction-level tile size (concept: GemmShape)
    typename InstructionShape_ = typename DefaultGemmConfiguration<
        OperatorClass_, ArchTag_, ElementA_, ElementB_, ElementC_,
        ElementAccumulator_>::InstructionShape,
    /// Epilogue output operator
    typename EpilogueOutputOp_ = typename DefaultGemmConfiguration<
        OperatorClass_, ArchTag_, ElementA_, ElementB_, ElementC_,
        ElementAccumulator_>::EpilogueOutputOp,
    /// Threadblock-level swizzling operator
    typename ThreadblockSwizzle_ = threadblock::GemmIdentityThreadblockSwizzle<>,
    /// Number of stages used in the pipelined mainloop
    int Stages =
        DefaultGemmConfiguration<OperatorClass_, ArchTag_, ElementA_, ElementB_,
                                 ElementC_, ElementAccumulator_>::kStages,
    /// Access granularity of A matrix in units of elements
    int AlignmentA =
        DefaultGemmConfiguration<OperatorClass_, ArchTag_, ElementA_, ElementB_,
                                 ElementC_, ElementAccumulator_>::kAlignmentA,
    /// Access granularity of B matrix in units of elements
    int AlignmentB =
        DefaultGemmConfiguration<OperatorClass_, ArchTag_, ElementA_, ElementB_,
                                 ElementC_, ElementAccumulator_>::kAlignmentB,
    /// Operation performed by GEMM
    typename Operator_ = typename DefaultGemmConfiguration<
        OperatorClass_, ArchTag_, ElementA_, ElementB_, ElementC_,
        ElementAccumulator_>::Operator,
    /// Complex elementwise transformation on A operand
    ComplexTransform TransformA = ComplexTransform::kNone,
    /// Complex elementwise transformation on B operand
    ComplexTransform TransformB = ComplexTransform::kNone,
    /// Gather operand A by using an index array
    bool GatherA = false,
    /// Gather operand B by using an index array
    bool GatherB = false,
    /// Scatter result D by using an index array
    bool ScatterD = false,
    /// Permute result D
    typename PermuteDLayout_ = layout::NoPermute,
    /// Permute operand A
    typename PermuteALayout_ = layout::NoPermute,
    /// Permute operand B
    typename PermuteBLayout_ = layout::NoPermute
>
class GemmUniversal : 
  public GemmUniversalBase<
    typename kernel::DefaultGemmUniversal<
      ElementA_,
      LayoutA_,
      TransformA,
      AlignmentA,
      ElementB_,
      LayoutB_,
      TransformB,
      AlignmentB,
      ElementC_,
      LayoutC_,
      ElementAccumulator_,
      OperatorClass_,
      ArchTag_,
      ThreadblockShape_,
      WarpShape_,
      InstructionShape_,
      EpilogueOutputOp_,
      ThreadblockSwizzle_,
      Stages,
      Operator_,
      SharedMemoryClearOption::kNone,
      GatherA,
      GatherB,
      ScatterD,
      PermuteDLayout_,
      PermuteALayout_,
      PermuteBLayout_
    >::GemmKernel
  > {

 public:

  using ElementAccumulator = ElementAccumulator_;
  using OperatorClass = OperatorClass_;
  using ArchTag = ArchTag_;
  using ThreadblockShape = ThreadblockShape_;
  using WarpShape = WarpShape_;
  using InstructionShape = InstructionShape_;
  using EpilogueOutputOp = EpilogueOutputOp_;
  using ThreadblockSwizzle = ThreadblockSwizzle_;
  using Operator = Operator_;
  using PermuteDLayout = PermuteDLayout_;
  using PermuteALayout = PermuteALayout_;
  using PermuteBLayout = PermuteBLayout_;
  static int const kStages = Stages;
  static int const kAlignmentA = AlignmentA;
  static int const kAlignmentB = AlignmentB;
  static int const kAlignmentC = EpilogueOutputOp::kCount;
  static ComplexTransform const kTransformA = TransformA;
  static ComplexTransform const kTransformB = TransformB;

  using Base = GemmUniversalBase<
    typename kernel::DefaultGemmUniversal<
      ElementA_,
      LayoutA_,
      TransformA,
      AlignmentA,
      ElementB_,
      LayoutB_,
      TransformB,
      AlignmentB,
      ElementC_,
      LayoutC_,
      ElementAccumulator_,
      OperatorClass_,
      ArchTag_,
      ThreadblockShape_,
      WarpShape_,
      InstructionShape_,
      EpilogueOutputOp_,
      ThreadblockSwizzle_,
      Stages,
      Operator_,
      SharedMemoryClearOption::kNone,
      GatherA,
      GatherB,
      ScatterD,
      PermuteDLayout_,
      PermuteALayout_,
      PermuteBLayout_
    >::GemmKernel
  >;

  using Arguments = typename Base::Arguments;
  using GemmKernel = typename Base::GemmKernel;
};

////////////////////////////////////////////////////////////////////////////////

/// Partial specialization for column-major output exchanges problem size and operand.
template <
    /// Element type for A matrix operand
    typename ElementA_,
    /// Layout type for A matrix operand
    typename LayoutA_,
    /// Element type for B matrix operand
    typename ElementB_,
    /// Layout type for B matrix operand
    typename LayoutB_,
    /// Element type for C and D matrix operands
    typename ElementC_,
    /// Element type for internal accumulation
    typename ElementAccumulator_,
    /// Operator class tag
    typename OperatorClass_,
    /// Tag indicating architecture to tune for.  This is the minimum SM that
    /// supports the intended feature. The device kernel can be built
    /// targeting any SM larger than this number.
    typename ArchTag_,
    /// Threadblock-level tile size (concept: GemmShape)
    typename ThreadblockShape_,
    /// Warp-level tile size (concept: GemmShape)
    typename WarpShape_,
    /// Instruction-level tile size (concept: GemmShape)
    typename InstructionShape_,
    /// Epilogue output operator
    typename EpilogueOutputOp_,
    /// Threadblock-level swizzling operator
    typename ThreadblockSwizzle_,
    /// Number of stages used in the pipelined mainloop
    int Stages,
    /// Access granularity of A matrix in units of elements
    int AlignmentA,
    /// Access granularity of B matrix in units of elements
    int AlignmentB,
    /// Operation performed by GEMM
    typename Operator_,
    /// Complex elementwise transformation on A operand
    ComplexTransform TransformA,
    /// Complex elementwise transformation on B operand
    ComplexTransform TransformB,
    /// Gather operand A by using an index array
    bool GatherA,
    /// Gather operand B by using an index array
    bool GatherB,
    /// Scatter result D by using an index array
    bool ScatterD,
    /// Permute result D
    typename PermuteDLayout_,
    /// Permute operand A
    typename PermuteALayout_,
    /// Permute operand B
    typename PermuteBLayout_
>
class GemmUniversal<ElementA_, LayoutA_, ElementB_, LayoutB_, ElementC_,
           layout::ColumnMajor,  // partially specialized on LayoutC
           ElementAccumulator_, OperatorClass_, ArchTag_, ThreadblockShape_,
           WarpShape_, InstructionShape_, EpilogueOutputOp_,
           ThreadblockSwizzle_, Stages, AlignmentA, AlignmentB,
           Operator_, TransformA, TransformB, GatherA, GatherB, ScatterD,
           PermuteDLayout_, PermuteALayout_, PermuteBLayout_> {
 public:

  using ElementA = ElementA_;
  using LayoutA = LayoutA_;
  using TensorRefA = TensorRef<ElementA const, LayoutA>;
  using ElementB = ElementB_;
  using LayoutB = LayoutB_;
  using TensorRefB = TensorRef<ElementB const, LayoutB>;
  using ElementC = ElementC_;
  using LayoutC = layout::ColumnMajor;
  using TensorRefC = TensorRef<ElementC const, LayoutC>;
  using TensorRefD = TensorRef<ElementC, LayoutC>;
  using ElementAccumulator = ElementAccumulator_;
  using OperatorClass = OperatorClass_;
  using ArchTag = ArchTag_;
  using ThreadblockShape = ThreadblockShape_;
  using WarpShape = WarpShape_;
  using InstructionShape = InstructionShape_;
  using EpilogueOutputOp = EpilogueOutputOp_;
  using ThreadblockSwizzle = ThreadblockSwizzle_;
  using Operator = Operator_;
  using PermuteDLayout = PermuteDLayout_;
  using PermuteALayout = PermuteALayout_;
  using PermuteBLayout = PermuteBLayout_;
  static int const kStages = Stages;
  static int const kAlignmentA = AlignmentA;
  static int const kAlignmentB = AlignmentB;
  static ComplexTransform const kTransformA = TransformA;
  static ComplexTransform const kTransformB = TransformB;

  using UnderlyingOperator = typename GemmUniversal< 
    ElementB,
    typename layout::LayoutTranspose<LayoutB>::type,
    ElementA,
    typename layout::LayoutTranspose<LayoutA>::type,
    ElementC,
    layout::RowMajor,    
    ElementAccumulator,
    OperatorClass,
    ArchTag,
    ThreadblockShape,
    WarpShape,
    InstructionShape,
    EpilogueOutputOp,
    ThreadblockSwizzle,
    Stages,
    kAlignmentB,
    kAlignmentA,
    Operator,
    kTransformB,
    kTransformA,
    GatherB,
    GatherA,
    ScatterD,
    PermuteDLayout,
    PermuteBLayout,
    PermuteALayout
  >::Base;

  using GemmKernel = typename UnderlyingOperator::GemmKernel;
  static int const kAlignmentC = EpilogueOutputOp::kCount;

  /// Argument structure
  using Arguments = typename UnderlyingOperator::Arguments;

private:

  UnderlyingOperator underlying_operator_;

public:

  /// Constructs the GEMM.
  GemmUniversal() { }

  /// Helper to construct a transposed equivalent for the underying GEMM operator
  static Arguments to_underlying_arguments(Arguments const &args) {
    return args.transposed_problem();
  }

  /// Determines whether the GEMM can execute the given problem.
  static Status can_implement(Arguments const &args) {

    return UnderlyingOperator::can_implement(to_underlying_arguments(args));
  }

  /// Gets the workspace size
  static size_t get_workspace_size(Arguments const &args) {
    
    return UnderlyingOperator::get_workspace_size(to_underlying_arguments(args));
  }

  /// Computes the grid shape
  static dim3 get_grid_shape(Arguments const &args) { 
    return UnderlyingOperator::get_grid_shape(to_underlying_arguments(args));
  }

  /// Computes the maximum number of active blocks per multiprocessor
  static int maximum_active_blocks(int smem_capacity = -1) {
    return UnderlyingOperator::maximum_active_blocks(smem_capacity);
  }

  /// Initializes GEMM state from arguments.
  Status initialize(Arguments const &args, void *workspace = nullptr, cudaStream_t stream = nullptr) {

    return underlying_operator_.initialize(to_underlying_arguments(args), workspace, stream);
  }

  /// Lightweight update given a subset of arguments
  Status update(Arguments const &args, void *workspace = nullptr) {

    return underlying_operator_.update(to_underlying_arguments(args), workspace);
  }

  /// Runs the kernel using initialized state.
  Status run(cudaStream_t stream = nullptr) {

    return underlying_operator_.run(stream);
  }

  /// Runs the kernel using initialized state.
  Status operator()(cudaStream_t stream = nullptr) {
    return run(stream);
  }

  /// Runs the kernel using initialized state.
  Status operator()(
    Arguments const &args, 
    void *workspace = nullptr, 
    cudaStream_t stream = nullptr) {
    
    Status status = initialize(args, workspace, stream);
    
    if (status == Status::kSuccess) {
      status = run(stream);
    }

    return status;
  }
};

////////////////////////////////////////////////////////////////////////////////

} // namespace device
} // namespace gemm
} // namespace cutlass

////////////////////////////////////////////////////////////////////////////////
